I did a writeup for this many eons ago. I guess maybe DavidB might have it somewhere in the archives.
The following directions are for small pieces of adhesive. If you want to remove window tint from a large window such as the rear view, use a big black garbage bag.
If it's sunny outside, do the following.
Materials needed:
- plastic cling wrap: ie, saran wrap, etc.
- black or dark colored plastic garbage bag
- household ammonia
- soap, water
- razor blade
- 000 steel wool
1. park the car outside in the sun
2. Take a piece of the plastic wrap and stick it over the area with the leftover adhesive or window tint.
3. Take a spray bottle, add some ammonia and water solution. Spary onto the plastic wrap and the adhesive/tint.
4. Cover the area.
5. Go outside of the car, and on the outside glass put a piece of dark colored plastic bag on the window in the same fashion (spray some solution on the glass so that the plastic stays).
6. Let sit in the sun so that the adhesive softens.
7. After about 15-30mins of sitting in the sun, the adhesive should have warmed and softened enough for you to remove.
8. Use your razor blade as necessary to remove the adhesive/tint.
9. Clean up with steel wool or whatever is your normal glass cleaning routine.
That's it! Hope this helps.